Hydraulic jack.



E. A. GATHMANN.

HYDRAULIC JACK.

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947,613. Panama .m 26, 1910.

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947,61 3. Patented Jan. 25, 1910.

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UNrTED STATES rnrnivr OFFICE.

Emu. A. GATHMANN,

OF- BETHLEHEM, PENNSYLVANIA, ASSIGNOR TO BETI-ILEHEM STEEL COMPANY, 0F BETHLEI-TEM, PENNSYLVANIA, A CORPORATION OF PENN- SYLVANIA.

HYDMULI'C JACK.

Spacication of Letters Patent. Patented J an. 25 1910.

Application led March 15, 18GB. FSerial No. 483,402.

vention, the two sections being taken in,

planes at right angles to -each other.

My invention relates to the class of hydraulic jacks, particularly portable jacks, and is designed to provide pump mechanism of a novel and eflicient character for Peffecting the operation of the jack.

A further object of my invention is to provide pump mechanism of this character hy" which the speed of the ram ofthe jack may be automaticallyV reduced in proportion to the load bein lifted. This enables a light load to be 1i ted rapidly and the Speed to be reduced in proportion as the load is increased. `It further .enables the ram of the jack to be run out rapidly to the load.

The power ofva hydraulic jack beingvinversely proportional to the speed of its ra'm travel, a small unit lift is necessary when the load is heavy, and my invention provides a pump which is so arranged that the volume ofthe liquid forced under the ram is automatically increased under a light load, but is reduced with a' heavyloadito meet thevarying conditions of usage The'natue of my invention will be best understood by reference to the accompanyf ing drawings, in which I have shown the Ypreferred embodiment thereof, it beingA pre-` mised, however, that various changes `can be made in the details of construction and arrangement of the parts'and that the pump mechanism there shown can be applied to other forms'of jacks, without departing from the spirit and scope oi my invention, as defined in the appended claims. ,i y

In these drawin s, the numeral 2 repre` ,sents a hollow jac cylinder having an integral closed bottom enbase 3, the cylinder and base being preferably made in one integral piece from forged steel, although it" may be constructed in any suitable manner. 4 designates an outer ram having a. lower portion 5 of larger diameter and provided have invented a new and useful4 ywith a cup-packing 6, `secured in a circumferential recess thereof 4b washer 7 Jandnut 8. The upper ,reduced diameter portion of this ram moves through a stop collar `9, Awhich is screwed or otherwise-secured within the upper end of the cylinder 2 and which' act as a stop against projects inwardly to diametery portion 5 ofy the lower v,or larger the outer ram.

10 designates the inner hollow ram or piston, having anintegralbottom 11, carrying a central' upwardly projecting pump cyhnder 12.V This pump cylinder ma bepformed `integrally with the base 11, as s own. The upper end of the ram piston 10 is provided with a dange 13, extendin over the upper end of the outer ram. 4,-and having screwed or otherwise secured thereto the ,enlarged hollow ram head 14. This head has an in- 'closed cavity or chamber 15, which,`together with the interior of the ram iston 10, is in operation filledv with a suitab e liquid, such as oil or alcohol .or 'a mixture'of alcoholand Lwater. When the rams are in the lowered position shown in the drawings, the flange 16 of the. ram head rests u on the stop ring 9, and sthe angegji?) of ih rests upon the upper end of the outer ram 4.

The jack as thus far described is substantia'll similar to one of the forms shown in my atentNo. 941,870, dated November 20, 1909. l

17 designates a pump rod having a horizontally extending eye 18, 'at its upper end portioh, which is engaged by a rocker arm ,19; projecting from a rocker shaft 20; This rocker shaft1 20 is rovided with suitable bearings in the ram ead, and has its exterpal portion provided with the usual o erating a stop portion 22, which coacts with a stationary stop 23, on the outside of the head to limit the downward movement of the handle,

'Supported on'a shoulder 24 at the upper e ram piston 10' andle 21, which has, in the form s own,

Secured to the piston rod 17, J

within the cylinder 26, is a combined piston and valve sleeve 27, whose upper piston end, working within the cylinder 2G, ias a cuppacking '28, and whose lower portion loose y lits over and surrounds the lower pump cylinder 12. A

29 desi ates a release valve forthe purpose hereinafter described. 30 is a discharge valve for the pump cylinder 12, these valves seating upwardly in the respective cham-r bers 31 and 32, which yare bored or otherwise formed in the bottom of' the hollow ram, piston, their lower ends heilig closed by the screw plugs 33 and 34.

35 desi ates 'springs which normally hold the va ves upwardl against their seats.

The stem of/ the va ve 29 `extends upwardly into the chamber in the piston ram -to a point directly below Vthe lower end of the sleeve 27, and the stem of the valve 30 projects upwardly into the chamber of the pump cylinder 12. The valve chamber 31 as a port or passage 36, which leads into the chamber of the cylinder 12 and the plug 34 of the ,valve 30v 1s formed with rooves or channels 3l', which lead downw'ar y into ther s ace 38 between thel hollow ram piston and `t e base of the cylinder.

ber is shown at 39, ,this valve controlling a 35 suitable tension-adjusting ort 40, which leads from the interior of the ollow ram into the pump chamber 41, of the u per cylinder 26. his u per pump chamlIJer 411s also provided wit an escape. port or passage 42, leadin into the chamer of the hol ow head an *normally closed by a spring-seated valve 43. The s rin 44 which seats this valve is rovid wit a evice 45, whereby the valve may be set to open at any desired pressure.

The pump rod 17 is' provided with a vertical port or passage'46, which communicates at its upper end with the pump chamber 41, by means of one or more branch'ports or passages47, and which,at its lower end, o ens into the lower prump chamber throug a check valve 48. his check valve seats upwardly in the pump rod, a screw plug 49,

bein inserted in the lower end of the pump rod elow said v'alve, the plug also securing the packing 50.

51 designates a packing for the inner ram piston, and 52designates packing or cleanlng rings which are interposed 'one between the stop ring 9: and the outer ram, and the other between the upper portions of the two rams, for the Ypurpose of preventing dirt or foreign matter from enterin v 53 designates afilling pug, in the ram head.

#The operation is as follows: The hollow head, the hollow ram piston and the pum chambers armas before described, filled Wit a suitable l uid. Upon the downstroke of the pump rol, the valve 39 is unseated, and liquid flows into the up er pump chamber. At the same time, the liquid in the lower chifmber is forced past the discharge `valve Yof the pump chamber and the rars.

32 and into the lifting chamber. n the ulpstroke of the pump rod, the valve 39 is' c oecd, and the liquid in the upper chamber, above the piston 28, is forced into thefport 47 andpassagc 46 and past the valve 48 into c the lower pump chamber. To lower the jack,

the sleeve 27 is engaged with the upwardly' projecting stem of the valve-29 to hold said valve open. The load on the jack will then force ,the liquid in the lifting chamber past the valve 32 (whichwill also be held open by the engagement with its stem of the lower end of the pump rod), and thence outwardly y rect proportion to the relative displacement During this lifting aud for about one-quarter the liftin movement of the inner r m, I obtain a iftin capacity equal tothe combined area of t e lower end of the two rams, since the up er end of theouter ram bears against the ange at the upper end of the inner ram of the piston. After the outer ram is stopped by the stopring 9, the inner ram piston continues upwardly for the rest of its stroke. r 1

It will be noted that the upper piston chamber 41v has aL nuch larger volume than t lowerfpumprchamber. In practice, I prefer to. make the "upper chamber of about five times thevolume ofithe lower chamber.

So long asthe load to be lifted does not exceed the pressureat which the valve 43 is set to open, it will (be seen that this larger volume, of`the chamber 41 provides forl a comparatively rapid lifting of the ram, so that a light load can be lifted rapidl or the ram run rapidly out ttf the load. hen, however, the load on the jack increases beyond the point at whichithe valve 43 is set to open, said valve will open and a large lpart of the liquid in the pump hamber41 familiar, an adjustment of valves must be madeby the operator when a change in the speed of the ram run-out is desired. VBy my invention, this change of speed is automatically effected and is regulated proportionally tothe load being lifted by means of the spring-controlled valve 43, which acts in the nature of a safety valve opening at a predetermined pressure per square inch. To

lower the' ram, the peratin lever is reversed, enabling the lower en ofthe sleeve -27 to be brought into contact with the upwardly projecting steni of the Avalve 29, and the lower end of the pump rod to bebrought into contact with the upwardly projecting stem of the valve 30. This unseats thesi; valves and allows the. liquid to flow back into the reservoir of, the ram.

While I have shown m invention as applied to duplex jacks of t 1e ty e shown and described', it will be obvious t at it may be applied to single jacks. It will also'be obviousathat many chan s ma be made in the details of constructlon an arrangement of the parts, without departing from my invention. Y

I claim:

1. In a hydraulic jack, a cylinder, a hollow ram piston seated therein, a double-acting lever-actuated pump within the ram piston and Garranged to force liquidunderneath the ram piston on both strokes,f and means for automatically regulating the amount of liqpid so forced according to the load being li ed; substantially as described.

2. In a hydraulic jack a hollow ram piston, having a hollow hea attached to its u 4per portion, a pump cylinder within t e lower part of the ram piston, a larger pump cylinder supported by the ram piston, a pump rod working in said cylinders, valve-l controlled v'means for admitting liquid to both cylinders, ports which connect both cylinders with the space below theram piston, and valves controlling said ort's said pump cylinders, pump rod and va ves being arranged to force liquid underneath the ram' piston during both strokes of the pump rod, substantially as described' Y 3. A hydraulic jack havinga cylinder, a hollow ram piston coperatilig therewith, a hollow ram head secured to said piston,

u n per and lower pump chambers carried by tlrie piston, said chambers being of different capacities, valve and port means wherebyliquid is forced from one of said chambers underneath the-ram durin both s rokes of the pump, the larger cylin er and t eflarger chamber having an'esca eopening, and an adjustable valve contro ling said opening, substantially as described.

4. In a hydraulic jack, the combination with a ram piston, of a double-acting leveractuated pump located within the ram piston and arran ed to force liquid below the said piston on oth strokes of the lever, and means for permittin the free escape of a portion of the liqui proportionally lto the load from one of the pum chambers on one stroke of the pump, su stantially 'as de scribed.

5. A hydraulic jack, comprising a cylin- ,lower `ber be der, a ram piston arrangpd to work in said cylinder, and having a ollow head, upper and ,lower pump Acylinder chambers, the lower' chamber bein within and a part of the .ram piston, an lthe upper one being Supported within 'the' ram piston, and a pump rod having istons of different-areas workingjn said cy inders, the largerV cylinder having an escape" opening, and an ad-y justable valve ontrollin the said opening, substantially as described. y

6. In a hydraulic jacl, a.hollow ramy iston having upper and lower pump cylin ers ofgdil'erent capacities, a pum rod Working in said cylinders, valve-contro led means for admitting liquid to said cylinders, ports connesting both cylinders with the space below the ram piston, and valves controlling said ports, the cylinder of larger capacity having an esca e opening and an adjustable spring- `control ed valve controlling the said opening, substantially as described.

In a h 'draulic jack, a hollow ram piston and a lower pump cylinder carried by the ram piston, an upper pxump cylinder of lar er capacity within t ve upper portion of t e piston, a pump rod having ist/ons of unequal areas workln in said cy inders, valve and port means vvA ereby liquid is forced underneath the `ram on both strokes of the pump, and means for automaticall regulating the amount of liquid so forced dilring one stroke ofthe ram, substantially as described.

r 8. In a hydiaulicjack',` a hollow ram piston and a hollow head carried thereby, an up er pump cylinder carried by the piston an havin a valved inlet passage communieating wit the' interior of the piston and an escapepassage communicating with the in-` `mg chamber be ow the raln, substantially as described. r

9. In a hydraulic jack, a hollow ram piston a hollow head carried thereby, upper and lowerfpump cylinders within the ram piston and having diilerent capacities, a pump rod having diil'erential piston areas working in the respective cylinders, a valved port in the ump rod connecting the pump chambers o the two' cylinders, said upper cylinder having an inlet port, and there ing a valved outlet port connecting the iston chamberwith a lifting chamidw the ram, the upper piston chamber having an esca e opening, and an adjustable automatica ly opening valve controlling said opening, said pump rod and cylinders being arranged to force liquid into said lifting chamber on both strokesof the rod; substantially as described.

10. In a hydraulic jack, a cylinder, inner and Jouter rams coacting with said cylinder, a

ollow head secured thereto, a

upper and larger 'havlng piston portions of of the rod; substanti double-acting pump located within theinner ram and arr to force liquid below both rams on both strokes, and a s ring-actuated' valve for automatically regu ting the volume of liquid forced under the ram during one stroke of the* iston accordi to kthe uload on the ram, su tially as ascribed.

11. A h draulic jack, comprising a cylinder, a hol` ow ram piston seated within the cylinder and having a hollow head, Said piston and head forming a reservoir for the actuating fluid, a lower ump cylinder within the lowem portion of the ramdpiston an plump cylinder tachahl ported within t e ram piston a pump r diierentI areas working in the respective cylinder, said upper cyllnder having a'valved inletport, and the pump rod having a' valved port connecting the two cylinders, and means for actuating the pum rod, said cylinders and rod being arrange to force liquid into actuating contact with the'ram iston"on-both strokes y as described. 12. A hydraulic jack` comprisinga cylinsup *Y mais der ,pa hollow /ra'm 'piston seated within the cylln'der and having a hollow head, said piston and head forming a reservoir for the actuating fluid, a lower fpump cylinder within the lower portion ol the ram upper and lar piston, a pump having piston portions o different areas working in the respective cylinders, said upper cylinder havinga valved inlet port, and the pump rod having a valved port connecting the two cylinders, and means for actuating the-pump rod, said cylinders and rod being ar nge to force llquid'into actuating contact with the ram piston on .both strokes of the rod; together with means for permittingthe escape of .a portion ofthe .liquid from. the `upper cylinder under redetermined conditions; substantially as dpescribed. In testimony whereof, I have hereunto set my hand.4 i Y EMIL A. GATHMANN. Witnesses: V

Enw. J. Gnomi', f GnE. SELLERS.

iston, an` pump cylinder etachably supported wit in the ram ro 

